Using WMS time dimension with rasters?

[Eric Bridger]

Alternatively, you can use Mapserver's variable substituion. See:
http://mapserver.gis.umn.edu/doc46/mapfile-reference.html#variablesubstitution

If you store your rasters with a time stamp as part of the name e.g.
modis_YYYYMMDDTHHMM.jpg, you can use the following in your map file:

DATA '/modis_files/%time%.jpg'

Your users would then need to add the &time=YYYYMMDDTHHMM parameter to
their GetMap requests.

Eric


On Mon, 2005-10-10 at 17:53, Paul Ramsey wrote:
> Jeff,
> 
> Support for the time dimension in rasters exists, you just have to  
> take a slight detour to get there.  You want to use a "tile index" in  
> your raster layer.  This is a vector file that contains one record  
> for each raster file.  The shape should be the outline of the  
> raster.  It should have at least one attribute, which contains the  
> file path to the raster file.  For time based data, it will contain a  
> second attribute, the date associated with the raster file.
> 
> The vector "file" can be any of the Mapserver vector formats, so it  
> can be shape file, or a postgis table, or an oracle table, etc.  You  
> can use the "tile4ms" (either part of mapserver or gdal, I am not  
> sure) command to create a tile index from a directory of data, though  
> it won't fill out a time stamp attribute for you.
> 
> So, when mapserver is told to draw an image, it will (a) first look  
> in the tile index to see what images fit the spatial and time extents  
> being requested then (b) open up those images and draw them into the  
> output image then (c) return the result.
> 
> Yours,
> Paul
> 
> Refractions Research
> www.refractions.net
> 
> 
> 
> On 10-Oct-05, at 11:22 AM, Jeff Schmaltz wrote:
> 
> > Hello,
> >
> > I am exploring the possibility of using MapServer to serve up MODIS
> > satellite imagery as a WMS.
> >
> > I have managed to create a working mapfile containing a single  
> > raster image
> > for a single day.  I need to to serve up a 2nd image which covers  
> > the same
> > geographic extents but is from a different date.  Ultimately, I  
> > want to
> > serve up years of daily images, hence my desire to use the time  
> > dimension.
> >
> > Searching the MapServer documentation - in the "WMS Time Support  
> > HOWTO", I
> > found the statement "wms_ timeitem: (Mandatory) this is the name of  
> > the
> > field in the DB that contains the time values".  I am surmising  
> > that "DB"
> > refers to database and that PostGIS is the open source database one  
> > would
> > use with MapServer.  From the PostGIS Manual FAQ "You can store  
> > point, line,
> > polygon, multipoint, multiline, multipolygon, and  
> > geometrycollections."
> >
> > Therefore, I have come to the conclusion that it is NOT currently  
> > possible
> > to use the WMS time dimension for raster data.
> >
> > 1) If I am wrong, can someone please point in the right direction  
> > to use the
> > time dimension in a WMS for rasters?
> >
> > 2) If I am right, can someone please tell me if support for time  
> > dimension
> > for WMS rasters is coming anytime soon in MapServer?
> >
> > Thank you,
> >
> > Jeff
> >
> > Jeffrey E. Schmaltz  (SSAI)
> > MODIS Rapid Response Team
> > NASA Goddard Space Flight Center
> > Building 33 Room G108  Code 614.5
> > Greenbelt, MD 20771 - USA
> > Voice: (+1) 301 614 5135
> > Fax:   (+1) 301 614 6015
> > E-mail: Jeff.Schmaltz at gsfc.nasa.gov
> > URL: http://rapidfire.sci.gsfc.nasa.gov
> >